| 1. |
- Cengic, Goran, 1978, et al.
(författare)
-
Definition of the Execution Model Used in the Fuber IEC 61499 Runtime Environment
- 2008
-
Ingår i: Proceedings of the 6th IEEE International Conference on Industrial Informatics. - 1935-4576. ; , s. 301-306
-
Tidskriftsartikel (refereegranskat)abstract
- The buffered sequential execution model (BSEM) for IEC 61499 function block applications is presented. Before the execution of the application the composite function blocks are flattened. The resulting application containing the basic and service interface function blocks is executed. The basic function blocks are put in the ready queue in the same order that they receive the input events, hence the word ldquosequentialrdquo in the name. Each basic function block keeps a queue of incoming events with their associated data, hence the word ldquobufferedrdquo in the name. Scheduling policy of the blocks is in the scheduling function while the execution policy of the received events is in the function block instance. The extended finite automata models suitable for formal verification of the proposed execution modelpsilas behavior are presented. The model may be analyzed using a discrete event systems tool called Supremica. The presented execution model is implemented in the Fuber runtime environment.
|
|
| 2. |
- Dust, Lukas, et al.
(författare)
-
Quantitative analysis of communication handling for centralized multi-agent robot systems using ROS2
- 2022
-
Ingår i: IEEE International Conference on Industrial Informatics (INDIN). - : Institute of Electrical and Electronics Engineers Inc.. - 1935-4576 .- 2378-363X. ; 2022-July, s. 624-629
-
Konferensbidrag (refereegranskat)abstract
- Multi-agent robot systems, specifically mobile robots in dynamic environments interacting with humans, e.g., assisting in production environments, have seen an increased interest over the past years. To better understand the ROS2 communication in a network with a high load of nodes, this paper investigates the communication handling of multiple robots to a single tracking node for centralized multi-agent robot systems using ROS2. Thereore, a quantitative analysis of two publisher-subscriber communication architectures and a comparative study between DDS vendors (CycloneDDS, FastDDS and GurumDDS) using ROS2 Galactic is performed. The architectures of consideration are a many-to-one approach, where multiple robots communicate to a central node over one topic, and the one-to-one communication approach, where multiple robots communicate over particular topics to a central node. Throughout this work, the increase in the number of robots at different publishing rates is simulated on a single computer for the different DDS vendors. A further simulation is done using a distributed setup with CycloneDDS. The simulations show that with an increase in the number of nodes, the average data age and the data miss ratio in the one-to-one approach were significantly lower than in the many-to-one approach. CycloneDDS was shown as the most robust regarding crashes and response time under system launch, while FastDDS showed better results regarding the data ageing.
|
|
| 3. |
- Keramidas, G., et al.
(författare)
-
Embedded reconfigurable computing: The ERA approach
- 2013
-
Ingår i: IEEE International Conference on Industrial Informatics (INDIN). - 1935-4576. ; , s. 827-832
-
Konferensbidrag (refereegranskat)abstract
- The growing complexity and diversity of embedded systems-combined with continuing demands for higher performance and lower power consumption-places increasing pressure on embedded platforms designers. The target of the ERA project is to offer a holistic, multi-dimensional methodology to address these problems in a unified framework exploiting the inter-and intra-synergism between the reconfigurable hardware (core, memory, and network resources), the reconfigurable software (compiler and tools), and the run-time system. Starting from the hardware level, we design our platform via a structured approach that allows integration of reconfigurable computing elements, network fabrics, and memory hierarchy components. These hardware elements can adapt their composition, organization, and even instruction-set architectures to exploit tradeoffs in performance and power. Appropriate hardware resources can be selected both statically at design time and dynamically at run time. Hardware details are exposed to our custom operating system, our custom runtime system, and our adaptive compiler, and are even visible all the way up to the application level. The design philosophy followed in the ERA project proved efficient enough not only to enable a better choice of power/performance trade-offs but also to support fast platform prototyping of high-efficiency embedded system designs. In this paper, we present a brief overview of the design approach, the major outcomes, and the lessons learned in the ERA project.
|
|
| 4. |
- Khan, Adnan, 1984, et al.
(författare)
-
On-the-fly conformance testing of safety PLC code using QuickCheck
- 2019
-
Ingår i: IEEE International Conference on Industrial Informatics (INDIN). - 1935-4576. ; 2019-July, s. 419-424
-
Konferensbidrag (refereegranskat)abstract
- In this paper, an approach based on the IOCOS testing relation to test safety PLC code using the tool QuickCheck is presented. Testing and validation of the safety PLC code is typically carried out on a physical system using checklists. These checklists are developed by engineers using system specification. However, due to the manual nature of checklist generation and execution, certain test cases can be overlooked and can lead to human accidents. The presented approach allows on-the-fly generation and execution of test cases, which expands the scope of testing by including test cases unconceived during checklist generation. Furthermore, it is demonstrated how errors in the safety PLC code are uncovered based on the IOCOS relation.
|
|
| 5. |
- Ljungkrantz, Oscar, 1978, et al.
(författare)
-
A formal specification language for PLC-based control logic
- 2010
-
Ingår i: Proceedings of the 8th IEEE International Conference on Industrial Informatics, INDIN 2010; Osaka; 13 July 2010 through 16 July 2010. - 1935-4576. - 9781424473007 ; , s. 1067-1072
-
Konferensbidrag (refereegranskat)abstract
- Formal verification, using model checking tools, is promising in developing (IEC 61131) industrial control logic. Formal verification requires a formal specification of the properties to be verified. Specifications in model checking tools are typically expressed using temporal logic. However, the standard temporal logic dialects are not well suited for control engineers who do rarely have a background within computer science. In this paper a new dialect of linear temporal logic, ST-LTL, is introduced that intends to be easier to use for control engineers than the existing dialects. The relation of ST-LTL compared to existing temporal logic dialects is analyzed. © 2010 IEEE.
|
|
| 6. |
- Priesterjahn, Claudia, et al.
(författare)
-
Runtime Safety Analysis for Safe Reconfiguration
- 2012
-
Ingår i: IEEE International Conference on Industrial Informatics (INDIN). - 1935-4576. - 9781467303118 ; , s. 1092-1097
-
Konferensbidrag (refereegranskat)abstract
- Modern technical systems are increasingly built to exhibit self-x properties as, e.g., self-healing or self-optimization. For this, they require adaptation at runtime. This is even true for embedded or mechatronic systems which often operate in safety- critical environments. There, the effects of the adaptation with respect to safety must be analyzed carefully. However, not all parameters needed for safety analyses, e.g., the concrete system architecture, are known at design time. Consequently, safety analyses need to be executed during runtime. Current approaches of runtime safety analysis typically react to anomalies that already occurred in the system. Thus, unsafe system states cannot be excluded completely. We present a runtime safety analysis that prevents system states with an unacceptable risk that have not yet occurred. For this, we generate the reachable component structures at runtime and analyze them with respect to risk. The system is modified such that component structures with an unacceptable risk are not reachable any more and are thus prevented.
|
|
| 7. |
- Ramezani, Zahra, 1988, et al.
(författare)
-
Evaluating Two Semantics for Falsification using an Autonomous Driving Example
- 2019
-
Ingår i: IEEE International Conference on Industrial Informatics (INDIN). - 1935-4576. - 9781728129273 ; 2019-July, s. 386-391
-
Konferensbidrag (refereegranskat)abstract
- We consider the falsification of temporal logic properties as a method to test complex systems, such as autonomous systems. Since these systems are often safety-critical, it is important to assess whether they fulfill given specifications or not. An adaptive cruise controller for an autonomous car is considered where the closed-loop model has unknown parameters and an important problem is to find parameter combinations for which given specification are broken. We assume that the closed-loop system can be simulated with the known given parameters, no other information is available to the testing framework. The specification, such as, the ability to avoid collisions, is expressed using Signal Temporal Logic (STL). In general, systems consist of a large number of parameters, and it is not possible or feasible to explicitly enumerate all combinations of the parameters. Thus, an optimization-based approach is used to guide the search for parameters that might falsify the specification. However, a key challenge is how to select the objective function such that the falsification of the specification, if it can be falsified, can be falsified using as few simulations as possible. For falsification using optimization it is required to have a measure representing the distance to the falsification of the specification. The way the measure is defined results in different objective functions used during optimization. Different measures have been proposed in the literature and in this paper the properties of the Max Semantics (MAX) and the Mean Alternative Robustness Value (MARV) semantics are discussed. After evaluating these two semantics on an adaptive cruise control example, we discuss their strengths and weaknesses to better understand the properties of the two semantics.
|
|
| 8. |
- Wong, S., et al.
(författare)
-
Early results from ERA embedded reconfigurable architectures
- 2011
-
Ingår i: 9th IEEE International Conference on Industrial Informatics, INDIN 2011, Lisbon, 26-29 July 2011. - 1935-4576. - 9781457704345 ; , s. 816-822
-
Konferensbidrag (refereegranskat)abstract
- The growing complexity and diversity of embedded systems combined with continuing demands for higher performance and lower power consumption place increasing pressure on embedded platforms designers. To address these problems, the Embedded Reconfigurable Architectures project (ERA), investigates innovations in both hardware and tools to create next-generation embedded systems. Leveraging adaptive hardware enables maximum performance for given power budgets. We design our platform via a structured approach that allows integration of reconfigurable computing elements, network fabrics, and memory hierarchy components. Commercially available, off-the-shelf processors are combined with other proprietary and application-specific, dedicated cores. These computing and network elements can adapt their composition, organization, and even instruction-set architectures in an effort to provide the best possible trade-offs in performance and power for the given application(s). Likewise, network elements and topologies and memory hierarchy organization can be selected both statically at design time and dynamically at run-time. Hardware details are exposed to the operating system, run-time system, compiler, and applications. This combination supports fast platform prototyping of high-efficient embedded system designs. Our design philosophy supports the freedom to flexibly tune all these hardware elements, enabling a better choice of power/performance trade-offs than that afforded by the current state of the art.
|
|
